Method and apparatus for forming mineral wool products



LL 1 I A E. R. POWELL Oct. 12, 1948.

METHOD AND APPARATUS FOR FORMING MINERAL WOOL PRODUCTS Filed Sept. 39. 1944 HIE.

lllillllll I INVENTOR Aka 4P0 f? fia 5W Q ATTORNEY Patented Oct. .12, 1948 METHOD AND APPARATUS FOR FORMING MINERAL WOOL PRODUCTS Edward R. Powell, North Plainfleld, N. 3., assignor to J ohns-Manville Corporation, New York, N. Y., a corporation of New York Application September 30, 1944, Serial No. 556,541

8 Claims. .(Cl. 154-27) The present invention relates to the-manufacture of mineral wool and, more particularly, to an apparatus and method for forming improved blankets or felts of mineral wool and similar fibers. The term "mineral wool" is employed herein in a generic sense to include fibers formed from rock, slag, glass, mixtures thereof, and like raw materials. The application is a continuation, in part, of my co-pending application, S. N. 502,- 572, filed September 16, 1943.

The invention has for its principal object the provision of an improved method and apparatus for collecting mineral wool fibers coincident with their formation, and forming a blanket therefrom, and is particularly directed to a method and apparatus for collecting a thin layer of fibers and for laying said layer in relatively wide, continuous folds on a receiving member to build up a blanket or felt of commercial thickness and width.

Anotherobject of the invention is the provision of a method and apparatus, as referred to above, including the application of a binder to the thin layer prior to the folding or lapping operation, whereby the built up blanket or felt includes a substantially uniformly distributed binder. The invention is particularly adapted for operation in conjunction with rotor type fiberizing apparatus in which molten mineral wool'forming material impinges against a rotor or rotors driven at high speed and is broken up into drops or masses which are thrown out by centrifugal force and drawn out into fibers or filaments.

A further object of the invention is the provision of an apparatus of the type referred to including a drum having a fiber-receiving surface rotating adjacent the fiberizing means, and means within said drum to cause deposit of the fibers in the form of a layer, and to retain said layer on the surface of the drum through a substantial arc of the rotation thereof.

A still further object of'the invention is the provision of an apparatus as described, including gaseous or fluid jets acting through the drum surface to remove the fibrous layer therefrom and to transfer it to further elements of the ap- Daratus.

My invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description of the invention which isto follow and to the accompanying drawing in which;

Fig. 1 is a diagrammatic, side elevational view witlrparts in section, and other parts broken material discharged from trough l2 strikes the 2 away, of an apparatus in accordance with the invention; and

Fig. 2 is a diagrammatic, end elevational view,

with parts broken away, of the apparatus of Fig. 1.

Referring now to the drawing, there is shown an apparatus comprising a raw material meltin furnace l0, which may be of any suitable type, such as a cupola, tank furnace, or the like. Furnace III has a discharge trough II by which a stream of molten slag, rock, glass, or other fiber forming raw material is drawn from the furnace, and is discharged into position to be contacted by a fiberizing means, preferably one or more rotors I4 driven at high speed by suitable means, such as mot ors,'indicated diagrammatically at I 6. The fiberizing apparatus is not shown in detail. In the fiberizing operation the molten rotor or rotors and is broken up thereby and converted into fibrous form.

In accordance with the instant invention, a drum iii, of relatively large diameter, is mounted for rotation in the direction indicated by the arrow in Fig. 1. The surface of the drum is made up of a foraminous or open-work material, such as perforated metal sheets, relatively coarse mesh screen, or the like, Metal sheets, having perforations of approximately 1" diameter and substantially uniformly spaced on 1%" centers have been successfully employed to form the drum wall. The drum is supported for rotation in a suitable manner to permit of the inclusion within it Of a suction hood and other means to .be described. For this purpose, as shown, the

drum may include a relatively rigid end structure or wall 20, which carries the foraminous peripheral wall 22. The end structure 20 is secured as by element 24 to a shaft 26 to rotate therewith. Shaft 26, mounted for rotation within bearings 28, carried by supports 30, is adapted to be driven at high speed by a suitable motor or other drive means (not shown) through the medium of a sprocket 32 and chain 34. The construction described above which supports the drum from one end only allows, as will be readily apparent, the mounting of non-rotatable elements of the apparatus in the drum through the open end thereof opposite end structure 20.

Within drum I8 there is provided a suction hood 36, connectedby means of a suction main 38 with an air exhausting device of any suitable type (not shown). The suction hood, supported by any suitable means (not shown) is in such fixed position within the drum as to draw air through a considerable area (hereinafter re ferred to as the fiber-receiving area) of the foraminous surface of the drum adjacent the fiberizing means I4. The hood may be sealed against the rotating parts of the drum, to prevent excess air leakage, in any suitable way. For purposes of example I have shown wipers secured adjacent the longitudinal edges of the upper and lower walls of the hood, the wipers bearing against the inner side of wall 22, Similar wipers may be employed at the ends of the hood. A shield 42, lying adjacent the inner surface of the drum, extends from hood 36 to a point substantially remote from the hood, as shown in Fig. 1. The shield is supported in a stationary position in any suitable manner, as by connecting it directly to the hood at one end, and securing the other end to an angle member 44 carried by the framing structure. One or more intermediate supports 45 may also be employed where necessary or desirable. The shield 42 may comprise a thin sheet of metal or other relatively imperforate material.

Fiberizing means l4 and the fiber-receiving area of the drum are preferably enclosed by a housing 46.

Means 48 are employed to strip the fibrous layor 49 formed on the drum. This means preferably comprises a pipe or nozzle member 50 .of a length to extend substantially across the drum, supported within the drum adjacent the end of shield 42. with a cap, pipe plug, or the like 52 and is provided along its length with a plurality of nozzles 54 directed toward the adjacent inner surface of the drum, the nozzles suitably comprising holes drilled through the pipe wall. Pipe 50 is connected with any suitable source of fiuid under pressure, for example a steam or compressed air line.

A binder applying device indicated at 56, comprising an elongated nozzle member or pipe extending substantially across the drum is supported to direct a binder spray against the felt shortly before it reaches the point where it is blown off the drum. The nozzle member has a plurality of nozzles, spaced the length thereof, suitably formed by drilling the pipe at regular intervals. Device 56 is connected to any suitable binder supply (not shown).

Located below drum I8 is a sloping conveyor 58, formed of an open wire mesh or other foraminous material, and supported on rolls 60 to be driven in the direction indicated by the arrow, by suitable means, not shown. It will be understood that the conveyor may lead in either direction, the construction shown being selected merely for purpose of illustration, and may extend to any suitable point where the lapper, described below, is located. A suction box 62, connected to a suction main 64 is mounted below the upper reach of conveyor 58 to create a fiow of air through the conveyor. A press roll 66 is preferably located above roll 60 at the lower end of the conveyor. The press roll is mounted for adjustment of the gap between it and conveyor 58 and is preferably driven by any suitable means (not shown) at a peripheral speed corresponding to the linear speed of the conveyor.

Below the end of conveyor 58 is a lapper, indicated generally at 68, adapted to deposit the layer 49 of the fibrous material carried by conveyor 53 in continuous folds or laps back and forth across conveyor I0. The latter conveyor extends at right angles to the lapper conveyors The pipe has its inner end closed off referred to below and is supported to be driven in either direction desired. In the construction shown it is driven to the left as indicated by the arrow in Fig. 2. Lapper 68 may be of a type commercially available, and heretofore employed in the textile arts, and hence is not shown in detail. It comprises, however, conveyors l2 and I4 driven to travel in the directions indicated by the arrows. Conveyor 14 is reciprocated so that its forward end 16 traverses uniformly back and forth across, or partially across, conveyor 10 to deposit layer 48 in the folds or laps previously referred to. Conveyor I2 is also reciprocated. though at a different speed and through a shorter distance of travel than conveyor 14, to provide a path for the layer of constant length between the point at which it leaves conveyor 58 and the point at which it is discharged from conveyor 14, to avoid bunching or tangling of the layer. The particular apparatus for the reciprocation of conveyors 12 and 14 has not been shown but, as indicated above, may be of any conventional or usual type.

In the operation of the apparatus described above, and in carrying out the method of the invention, suction boxes 30 and 82 are connected through their respective ducts with any desired exhausting means to create a flow of air through the foraminous surface of the drum at the fiberreceiving area, and through the upper reach of conveyor 58, respectively. Drum i8 is rotated at a relatively high speed, such as to have a surface speed of. say, 1,000 to 3,000. per minute. A suitable fluid under pressure, preferably steam, is supplied to nozzle member 50 of means 48, the fluid issuing in a plurality of jets from the nozzles 54, spaced along the length of the nozzle member.

The molten mineral material, delivered by trough l2, strikes the high speed rotors l4 and is converted thereby into relatively fine threads or fibers. These fibers are collected on the surface of drum iii to form a layer thereon by the inward movement of air through the surface of the drum created by suction box 36. The speed of rotation of the drum is controlled relatively to th rate of fiber formation to form a very thin', open layer of the fibers on the drum, say one having a, thickness of /5" or less. It will be appreciated that, for purposes of illustration, this layer is shown of exaggerated thickness in the drawing.

The thin lap or layer adheres to the surface of the drum sufiiclently to be carried around to the point where it meets the jets issuing from nozzle member 50. Shield 42, adjacent the inner surface of the drum, and extending from suction box 36 to the nozzle member, assists in maintaining the lap or layer on the drum, in that it prevents outward movement of air through the foraminous surface of the drum, which would tend to force off the fibrous layer before it reaches the blow off point. Just before the fibrous layer is removed from the drum surface by means 48, it is carried through the path of the binder spray issuing in atomized or finely divided state from binder applying means 56, the binder being supplied in sufiicient amount and with sufilcient force to become distributed substantially uniformly throughout the thin layer. This arrangement lends itself to economic use of the binder. Any of the binder which passes through the layer is car- 'ried with the drum and is forced off into the m a product of substantial thickness.

the layer on upper conveyor 12 of lapper 58. Lapper 88 is driven at a rate correspondin to the production of the material and lays the layer in continuous folds back and forth on conveyor 10. The thickness of the blanket formed on conveyor ill will depend upon the speed of the conveyor relative to the rate of delivery of the fiber layer. For example, conveyor 10 may be driven at such a relatively slow speed that the blanket is composed of it) or more overlapping folds form- The blanket built up on conveyor 10 is carried to any suitable location where further operations may be carried out. These operations will normally include compressing the blanket and setting the binder, dividing the blanket into batts or pads of commercial size and packaging the same. Other or additional finishing steps may be employed.

The binder supplied by means 56 may be of any of the conventional materials employed for this purpose, such as asphalts. drying oils, resins,

waxes and the like. Due to thethin loose characteristics of the layer built up on the drum, such binders when applied in finely divided form to the thin open layer, as described, are substantially uniformly distributed throughout the layer with the result that the blanket formed on conveyor 10 carries a substantially uniformly disseminated binder throughout.

The method and apparatus of the instant invention provide'for the production of a blanket or felt with highly resilient structure. For example, a plurality of batts made as described above to include a resin binder, have been piled up to a thickness of say 24", and the pilethen compressed to a 7 /2" thickness and stored for 2 months in hot weather. Upon release of compression, the batts regained substantially their original thickness. Also, the invention permits the production of materials of very low density, say, as low as 1 to 1 /2 lbs. per cubic foot. Products of any desired thickness may be produced by proper control of the speed of conveyor 10 relative to the rate of fiber formation,

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to but that further objects and advantages thereof will become apparent to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

What I claim is:

1. In an apparatus for the manufacture of mineral wool felt or the like having fiberizing means for disintegrating a molten material into fibers, an open-work surface adapted to receive a layer of fibers thereon, suction means behind said surface adjacent said fiberizing'means, and a shield behind said surface extending from adj acent said suction means and in the direction of rotation of said drum to a point removed from said suction means, and means beyond said shield to remove said fibrous layer from said surface.

2. In an apparatus having means for converting a molten material into fibers, a rotatable drum having an open-work fiber-receiving suri'ace,-suction means behind said surface adjacent said first-named means, and a shield behind .said surface extending from adjacent said suction means and in the direction of rotation of said drum to a point removed from said suction means, and means beyond said shield to remove said fibrous layer from said drum.

' 3. In an apparatus having means for converting a molten material into fibers, a rotatable drum having .an open-work fiber-receiving surface, suction means behind said surface adjacent said first-named means, and a shield behind said surface extending from adjacent said suction of fibers on said area, means for rotating said drum at high speed relative to the rate of fiber deposit whereby a thin layer of fibers is formed on said drum, a conveyor below said drum and means located within said drum and above said conveyor for blowing a gaseous medium through the surface of the drum to remove said layer from said drum.

5. In an apparatus having means for converting a molten material into fibers, a rotatable drum having a perforate fiber-receiving area adjacent said means, means for causing deposit of fibers on said area, means for rotating said drum at high speed relative to the rate of fiber depositwhereby a thin layer of fibers is .formed on said area, means for applying an atomized binder to said layer on said drum, a conveyor below said drum, means located within said drum and above said conveyor for blowing a gaseous medium through said drum to remove said layer from said drum whereby said layer is deposited on said conveyor.-

6. The method comprising converting a molten material-into fibers, depositing said fibers in the form of a thin, continuous layer on a rotating surface, blowing a binder spray against the outer face of said layer while on said surface, carrying said layer on said surface to'a point remote from the place of'deposit of said fibers but adjacent said binder spray and blowing said layer from said surface, in a direction to intercept binder particles carried along said layer, by the action of gaseous jets acting through said surface.

7. In an apparatus having mean for converts in a molten material into. fibers, an open-work fiber-receiving surface adjacent said means, means for causing deposit of fibers on said surface, and means for moving said surface at high speed relative to the rate of fiber deposit whereby a thin layer of fibers is formed thereon, the improvement comprising means for discharging a binder spray against said layer on said surface, and means adjacent but forwardly of said binderdischarging means to force the layer outwardly from said surface in a direction to intercept binder particles carried along said layer.

8. In an apparatus having means-for converting a molten material into fibers, a rotatable drum having an open-work fiber-receiving surface, means for causing deposit of fibers on said 7 surface, and means for rotating said drum at high speed relative to the rate of fiber deposit whereby a layer of fibers is formed thereon, the improvement comprising means for spraying a binder on said layer while carried on said drum, and means adjacent but forwardly of said binderspraying means to force the layer outwardly from said drum in a direction to intercept binder particles carried along said layer.

EDWARD R. POWELL.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date I Borcholt et a1. Nov. 15, 1932 McClure June 6, 1933 Jackson Apr. 23, 1935 Vieweg Mar. 8, 1938 Carson Aug. 16, 1938 Thomas Mar, 12, 1940 Siegfried May 28, 1940 Simpson Feb. 4, 1941 Von Pazsiczky Nov. 2, 1943 

